The present invention relates to a leakproof carton for packaging separate food items or the like, and more particularly to a carton having multiple compartments formed of a paperboard blank and particularly adapted for use with microwavable ready-to-eat meals.
In the past several years, there has been substantial research and development in the packaging field along the lines of leakproof cartons/trays particularly adapted for microwave use. The most popular type of these cartons is formed of paperboard coated with a thin plastic film, such as polyethylene. The cartons are pre-formed with fold lines and cut so as to be easily erected on automatic packaging machines. As thus formed, the cartons are not only relatively low cost and microwavable, but are also popular because they are relatively environmental friendly.
One of the most popular types of cartons in this field is exemplified by the invention set forth in U.S. Pat. No. 4,304,352, Flanged Tray With Gusset Corners, issued Dec. 8, 1981 and assigned to the present assignee. This carton is leakproof and easy to form with corners constructed of attached gusset panels. When erected, the gusset panels are overlapped and sealed against the adjacent side panel. The pair of gusset panels form the leakproof corner by being connected by a fold line to each other and fold lines to the adjacent side panels.
The inside gusset panel includes a cut-out portion allowing efficient sealing and attachment of the outer gusset panel against the side panel of the carton.
Other attempts have been made in the past to improve on this type of carton or tray. These efforts have been concentrated generally in the area of refinements in the coated paperboard, different gusset/panel arrangements, modified sealing flange arrangements and refined carton opening concepts.
In addition, in the past, there has been some attempt to provide successful multi-compartment cartons. In this regard, the efforts are focused in providing separate rectangular compartments separated by a divider panel. An example of this type of effort is illustrated in U.S. Pat. No. 3,876,132, entitled Multi-Compartment Tray and issued Aug. 8, 1975. Success with this type of carton has been limited due to several shortcomings. The carton is bulky, overweight and requires additional full depth, outside flaps along the side panels in order to provide sufficient strength. This feature also makes the carton blank overly expensive.
This prior art carton is also unsuited for small servings of food items and the like since to reduce the volume of the compartments results in compartments too narrow to fill and/or too restricted to conveniently remove the food item during eating, as is frequently desired when using this type of carton.
Accordingly, there is identified a need for an improved paperboard carton having multiple compartments and more adapted to holding a plurality of different food items in a leakproof fashion. The carton needs to be adapted for holding relatively small portions, such as single helpings so that the carton can be used as a ready-to-eat or TV tray type carton. Most importantly, the carton should be designed to be reinforced for stability and at the same time easy to erect on automatic machinery from a paperboard blank using minimum paperboard for economy.